2. Field of the Invention
The invention relates to an apparatus and method for compressing a video signal, in general, and specifically relates to an apparatus and method wherein red, green and blue color video signals are inputted into an apparatus, and a brightness signal and at least two color difference signals are generated therefrom, encoded and stored in a memory. The signals may then be decoded and combined to form a close approximation of the original video signal The brightness signal is encoded using pulse code modulation and the color difference signals are encoded using differential pulse code modulation to reduce memory storage requirements.
2. Related Art
General methods for encoding color video signals are known in the art. For example, systems for digitally transmitting color television signals are known, wherein color signals are divided into various components and the components are encoded. The encoded signals are fed into a time multiplex combiner to obtain a serial output data stream.
Other examples of known signal encoding methods provide a data compression system for transmitting data at a reduced data rate; a color television transmission system for transmitting encoded signals at half the input rate; and a color video signal encoder which encodes color signals into a plurality of variable length words which are then serially transmitted to a buffer.
Still other color video systems use pulse code modulation techniques to encode each primary color signal of a color video system. Thus, in a typical system comprised of red, green and blue video signals, three identical pulse code modulation encoders are required to encode and store the color signal.
In the known systems described above, however, the electronic circuitry necessary to implement the encoding and storage functions is disadvantageously complex, resulting in increased cost, size, weight and power dissipation of the video signal compression and encoding system.